The present invention relates to carbon black and compositions containing the carbon black. More specifically, the present invention relates to particular types of carbon blacks which promote beneficial properties in compositions such as ink compositions.
Colorants, such as carbon black, are a standard ingredient in compositions such as ink and coating compositions. These ink compositions include lithographic and flexagrophic inks wherein performance properties are generally desired by the end users. There is a continuing desire on the part of ink manufacturers to improve the properties of ink such as, reducing the cure energy needed to cure the ink and provide ink compositions that have improved storage stability. With respect to storage stability, the viscosity of the ink can greatly increase over time due to evaporation or other reasons. Thus, a goal of ink manufacturers is to provide inks that do not have an increase in viscosity over time since this is an undesirable property when the ink finally is used.
Overcoming one or more of the above-identified described disadvantages would provide an improved ink composition to the industry.
A feature of the present invention is to provide a carbon black which provides beneficial properties to compositions such as ink compositions.
Another feature of the present invention is to provide ink compositions which overcome one or more of the above-described disadvantages.
A further feature of the present invention is to provide an ink composition which requires less cure energy and/or has improved storage stability.
Additional features and advantages of the present invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention will be realized and attained by means of the elements and combinations particularly pointed out in the description and appended claims.
To achieve these and other advantages, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention relates to a carbon black having a moisture content of at least 0.5% and/or a volatile content of from about 1.5% to about 3.5% and at least one of the following properties: an Iodine number of from about 40 mg/g to about 75 mg/g, a DBP absorption of from about 40 cc/100 g to about 70 cc/100 g, a tint strength of from about 70 to about 100; and/or a nitrogen surface area of from about 40 to about 75 m2/g.
The present invention further relates to compositions containing the above-described carbon black, such as, but not limited to, ink compositions containing the above-described carbon black along with, for instance, at least one liquid vehicle or carrier.
The present invention also relates to a method to reduce the cure energy of an ink by using the above-described carbon black.
The present invention further relates to a method to improve storage stability using the above-described carbon black in an ink composition.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide a further explanation of the present invention, as claimed.